The present disclosure relates to triphenylamine derivatives, electrophotographic photosensitive members, and image forming apparatuses.
Electrophotographic photosensitive members are used as image bearing members in electrophotographic printers and multifunction peripherals. An electrophotographic photosensitive member for example includes a conductive substrate and a photosensitive layer located either directly or indirectly on the conductive substrate. An electrophotographic photosensitive member in which one layer implements a charge transport function by mainly containing a charge transport material and another layer implements a charge generation function by mainly containing a charge generating material is referred to as a multi-layer electrophotographic photosensitive member. An electrophotographic photosensitive member in which one layer includes both a charge transport material and a charge generating material, and thus in which the one layer implements both a charge transport function and a charge generation function, is referred to as a single-layer electrophotographic photosensitive member.
One known example of a charge transport material that can be contained in an electrophotographic photosensitive member is an arylamine-based compound. Furthermore, a known arylamine composition contains a specific ratio of geometric isomers (cis-isomer and trans-isomer) of an arylamine-based compound.